Ignition timer



July 24, 1923. 1.462.860

J. H. HUNT IGNITION TIMER original Filed Jan. 2. 191a 1537555555 5 i 9% 2% J .41 W4 1427; 17:575.

Patented July 24, 1923.

UNITED STATES 1,462,860 PATENT OFFICE.

JOHN H. HUNT, OF DAYTON, OHIO, ASSIGNOR TO THE DAYTON ENGINEERING LABORATORIES COMPANY, A. CORPORATION OF OHIO.

IGNITION TIMER.

Original application filed Ianuary 2, 1918, Serial No. 209,845.

December 11, 1919.

engines, and more particularly to the timing mechanism of such systems.

This application is a division of my coending application Serial No. 209,845, filed anuary 2, 1918.

One ofthe objects of the present invention isto provide means for eliminating the chatter of the timercontacts which ordinarily takes-place in ignitionsystems wherein the timer'cam actuates the co'ntact arms to open and close the primary circuit. p

--In carrying out this=object it is a further object of the present invention to provide means for preventing the separation of the contacts by absorbing the energy of impact, due to the opening and closing of the contacts, with the result that the contacts will remain in circuit closing relation until the cam tends positively to effect a subsequent separation of the contacts.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing, wherein a preferred embodiment of the present invention is clearly shown.

In the drawing:

The figure is a plan view of one form of timer mechanism embodying the present invention. and a wiring diagram showing the application of the timer mechanism to an ignition system.

Referring to the drawing. 20 is an arm of light construction pivoted upon a Stud 22 by means of a hub 21. Stud 22 is mounted upon the timer cup 40. but insulated therefrom by an insulating member 22. Arm 20 carries a cam follower 23 which is engaged at intervals by means of a cam 24 carried by an engine driven shaft 25. The free end of arm 20 carries a contact 26 which coop erates with contact 27. which is mounted upon a support carried by the timer cup 40. A spring 51 is fixed at one end to a Divided and this application filed Serial No. 844,204.

bracket 52 mounted upon insulating pad 53,

and extends alongside of said arm. A block of rubber 54 is vulcanized upon said arm,

and the free end 55 of spring 51 bears thereupon. A clip 56 is secured to spring 51 and serves to retain the said spring in proper position, and to conduct current passing through wire 45, bracket 52 and spring 51,

into hub 21 and arm 20. y

In the wiring diagram, 41 indicates the primary winding of an induction coil and 42 the secondary winding. One end of the secondary winding42 is connectedwith a-distributor 43 and the other end of-the secclosed. and the contacts 26 and 27 are in contact closing position. the be completed.

- When the pressure of spring 51 is applied to arm 20 through the soft rubber cushion. the energy of the impact contact 26. tending to rebound from the contact 27. will be absorbed to a large extent by the cushion 24. The action of the rebound block 54 in absorbing the energy of the impact and preventing rebound is due to elastic. hvsteresis. That is, when the rubber block is placed initially in the proper state of compression in spring 51 and is suddenly released from this state. the rubber block has the property of slowly returning to its initial shape when this additional pressure is removed. While the rubber is preferred as a cushioning material, it will be understood that other substances may be used which have elastic hysteresis under the conditions referred to.

While the block of rubber 54 is preferably vulcanized upon the arm 20. it is to be understood that the rubber block 54 could be vulcanized upon the spring 51 instead.

While the form of mechanism herein shown and described constitutes a preferred form of embodiment of the invention. it is to be understood that other forms might be adopted. all coming within the scope of the claims which follow.

\Vhat I claim is as follows:

1. In a timer mechanism, the combination with a support; of a pivoted arm having a hub mounted upon the support, but insulated therefrom; acontact carried by the arm; a second contact carried by the support; a cam member cooperating with the arm to separate the contacts; a bracket mounted upon the support, but insulated therefrom; aleaf spring having one end thereof attached to the insulated bracket, and another portion partly encircling the .hub of the arm, and the free endextending alongside the arm; a block at elastic matei-ial exhibiting elastic hysteresis located between the free end of the spring and the arm; and a clip attached to the spring and bearing upon the arm hub.

2. Tan timer mechanism, the combination \\'ith cooperating contacts; of a movable member of metallic material carrying one of the contacts; means cooperating with the movable member to effect separation of the contacts; and means for bringing the contacts together after separation and absorbing the energy of impact, comprising a spring and a block of rubber exhibiting elastic hysteresis interposed between the spring and the movable member and vulcanized upon the movable member.

3. In a timer mechanism; the combination with a support; of an arm pivotally mounted-upon the support; a movable timer contact carried by the arm; a stationary timer contact carried by thesupport; an engine driven cam cooperating with the arm to separate the contacts; aleafsp ing having one end attached to the support and the free end of said spring extending alon side the arm; and a block-of elastic materiel exhibiting elastic hysteresis located between the free end ofithe spring and the arm.

4. In a timer mechanism, the combination with a support; of cooperating timer contacts; a movable member carrying one of the contacts and .inounted u on the support; means cooperating with itihe, movable member to efiect the separation of the contacts; and means for bringing the contacts together after separation and absorbing the energy of impact bf the contacts, said means comprising a spring and ahloek of elastic material exhibiting elastic-t hysteresis interposed between the spring and the movable member and permanently secured to the movable member.

5. In a timer mechanism; the combination with a support; of cooperating timer contacts; a movable member carrying one of the contacts and mounted upon the support; means cooperating. with t e movable member to effect the separation. of the 'contatits;

and means: fo'l bringing thi contacts together after separation and absorbing the energy of impact of:the contacts said means comprisinga-spring and a. bloc of-rubber exhibiting elasticwhysteresisinterposed betiveenthe sprin and-the. movable member, said block-10f cured upon the-movable member;

In testimony whereo'f'I aifix-mTy-signahire. 1 w"freer H;

Withessess- 1 Mnmmohasn; Hem Smmmmmtom her being permanentl 53;. 

